Stapling machine



July 25, 1933.

E. KRANTZ STAPLING MACHINE Filed Feb. 28, 1931 2 Sheets-Sheet l July 25, 1933. E. KRANTZ STAPLING MACHINE 2 Sheets-Sheet 2 Filed Feb. 28, 1931 Patented July 25, 1933 UNITED STATES PATENT EDWARD mm'z, OF CHICAGO, ILLINOIS, ASSIGNOR, BY MESNE ASSIGNMENTS, TO A. L. HANSEN MFG. (70., OF CHICAGO, ILLINOIS, A CORPORATION OF ILLINOIS STAPLING MACHINE Application filed February 28, 1931. Serial No. 519,212.

This invention has to do with staplin machines of the type used quite extensive y 1n ofiices, stores and other places for the purpose of binding several sheets of paper or other material together with fine wire staples.

One of the principal objects of the'invention is to provide a novel stapling machine in which the staples are driven by means of a s -actuated hammer.

h ther important object is to proylde, in such a machine, means for regulating the force with which the staples are driven, whereby to obtain uniformity and compensate for various thicknesses of pape r.

Another object is to provide an operating arrangement which insures the proper positioning of the coacting parts of the machlne at the time that the staple is driven.

Many other objects and advantages of the invention will be apparent to those skilled in the art upon a full understanding of the construction, arrangement and operation of the improved machine.

'One form of the invention is presented herein by way of exemplification, but it will of course be appreciated that the invention is susceptible of embodiment in other structurally modified forms coming equally within the contemplated scope of the appended claims.

In the accompanying drawings:

Fig. 1 is a side view of the improved stapling machine;

Fig. 2 is a top view of the same;

Fig. 3 is a front end view;

Fig. 4 is a rear end view; v

Fig. 5 is a vertical longitudinal section through the machine, taken on the line 5-5 of Fig. 2, showing the position of the driving parts before the stapling operation;

Fig. 6 is a similar sectional view, showing the driving parts just after the spring has been compressed and just before the hammer is released;

Fig. 7 is a vertical transverse section, taken on the line 7-7 of Fig. 1;

Fig. 8 is a vertical transverse section, taken on the line 8-8 of Fig. 1;

Fig. 9 is a fragmentary plan view of the base, showing the changeable die; and

Fig. 10 is a fragmentary horizontal sec tion, taken on the line l0 10 of Fig. 1.

The machine includes a sheet metal base 10 and a sheet metal arm 11. The arm 11, which is substantially coextensive with the base, is positioned directly above the latter, and the rear end of the arm is pivoted to the rear end of the base at 12. The front end of the base 10 supports a die 13 which is provided with a transversel disposed clinching groove 14 (see Fig. 9; formed into an enlarged head '15 which contains the staple-driving mechanism of the machine.

The staples 16 tobe driven are U-shaped and are positioned in a guideway 17 of U- shaped cross section, which guideway extends longitudinally of the arm for practically the full length of the latter. The staples, which are preferably cemented together in large numbers, are inserted in the guideway 17 at the rear open end of the lat ter and are moved forwardly in the guideway by a sheet metal follower 18 of U-shaped cross section which fits into the guideway behind the staples. The follower 18 is connected at 19 to one end of a spring 20 which is spirally wound about and attached to a core 21 in the head of the arm. The core 21 is wound up in a manner hereinafter described to place the spring under tension. The foremost staple in the guideway is pressed by the action of the spring 20 against the rear face of a vertically extending blade 22 which reciprocates in a guideway 23. The guideway 23, which intersects with the front end of the guideway 17, is formed between two machined blocks 24 and 25 at the front end of the arm and opens downwardly in register with the clinching groove 14: in the die 13.

In the normal position of the arm 11, the front end of the latter is elevated a short distance above the front end of the base 10 by means of an upwardly spring-pressed plunger 26 which is reciprocally mounted in the base just forwardly of the pivot" 12, in contact with the bottom of the arm (see Fig. 5). The vertical distance between the front end of the arm and the front end of the base The front end of the arm 11 is may be increased or diminished b turnin a nut 27 on the lower screw-threa ed end 0 the plunger in either direction. If desired,-

. in a cylindrical bore 30 which is formed in "ton the front portion of the head 15.

A coil spring 31 is positioned in the bore 30 above the hammer 28. The lower end of the spring 31 seats in a socket 32 which is formed in the top of the hammer, while the upperend of the spring abuts against a vertically adjustable plate 33 in the bore. The plate 33 is in threaded enga ement with the lower portion of a screw 34, ut is prevented from turning within the bore by a small e 35 on the front edge of the plate which ro ects through a vertical slot 36 in the ront face of the head. The screw 34 is mounted in a cap 37 which fits over the upper cylindrical front end of the head and is detachably secured thereto by a bayonet joint 38. The screw 34 is free to rotate in the cap 37 but is locked against vertical movement with respect thereto.

A knurled head 39 is provided on the upper end of the screw 34. When the head 39 is turned, the plate 33 is moved either up or down in the bore, depending upon the dimotion in which the head is turned. By moving the plate 33 downwardly, any desired amount of compression may be set up in the spring. If the staple 16 to be driven is required to penetrate through a large number of sheets of paper or other material, a greater compression of the spring is required than when the staple is to penetrate through a small number of sheets. The -front face of the head 15 alongside the slot 36 may ad-.

vantageously be calibrated at 40 (see Fig. 3) to indicate the correct position of the'tongue 35 for any particular number of sheets.

The hammer 28, together with the blade 22, is retracted against the resistance of the sprin 31 by means of a handle 41. The handle 4 is located behind the head 15 and extends forwardly through a slot 42 in the rear portion of the latter. The handle is pivoted to the head by means of a cross pin 43, and is normally maintained in an elevated position by means of a spring 44. The rear end of the handle-where the operating pressure is applied-is located a little in front of the ulky material into the throat of pivotal axis of the arm 11. The front end of the handle terminates just rearwardly of the bore 30 behind a cross web 45 in the head and carries a downwardly extending do 46.-

The dog 46 is pivoted to the front end 0 the handle at 47 and is pressed against the rear face of the hammer 28 by means of a spring 48.. The lower free end of the dog is provided with a hook 49 for enga ement within a recess 50 in the rear face 0 the hammgr, and is also provided, above the hook 49, with a beveled surface 51 for coaction with the lower edge of the cross web 45.

When pressure is initially applied to the handle 41 to depress the latter, such pressure will first swing the arm 11 downwardly into firm engagement with the upper surface of the work resting on the die 13. As-the pres sure on thehandle is'continued, the handle will move downwardly and the hook 49 on the lower end of the dog 46, being in engagement with the recess 50 in the hammer, will edge of the cross web 45 and will be cammed rearwardly, thereby disengaging the hook 49 on the dog from the recess 50 in the hammer. As soon as this occurs, the hammer will be forced downwardly at a high rate of speed I under the action of the spring 31, and the foremost staple 16 beneaththe blade 22 will be driven by. the latter through the sheets of material on the die and clinched in the groove 14.

The core 21 which carries the spring 20 is held in place by a pin 52 (see Fig. 7). The pin 52 extends through a circular aperture 53 in one of the side walls of the head and through a squared aperture 54 in the other side wall, and is provided with a squared of the pin. The end of the pin opposite the .nut 56 is provided with a head 58 which is slotted for the reception of the end of a screw driver. 1

In order to increase the tension on the spring 20, it is merely necessary to back the nut 56 off for a distance a little more than 1 15 portion 55 which interfits non-rotatably with the thickness of tlie adjacent side wall, push the pin out a corresponding ,distance so that the squared portion 55 is clear of the squared aperture 54, and then turn the Head 58 by means of a screwdriver. As soon as the desired tension on the spring 20 has been obtained, the pin 52 is pushed back into its original position, with the squared portion 55 in the squared aperture 54, after which the nut 56 is screwed up tight a ain. This ar-- rangement provides a very simple and eflicient means of adjusting the tension of the spring.

The pivotal connection between the base 10 and the arm 11 may advantageously consist of an upwardly opening U-shaped sheet metal bracket 59 (see Fig. 8). The bracket is positioned with the horizontally extend-.

ing portion 60 thereof against the under surface of the base and with the vertically extending side portions 61 thereof in slots 62 formed in the top ofthe base adjacent the sides of the latter. The horizontally extending portion 60 of the bracket may be secured to the base by rivets or other suitable means. The vertically extending portions 61 of the bracket support a transversely extending bolt 63, which bolt is provided at one end with a headed screw plug 64:.

The arm 11 is provided adjacent the rear end thereof with two downwardly extending ears 65 which fit snugly between the side portions 61 of the bracket, and the bolt 63 extends through apertures in the ears 65.

The die-13, instead of being rigidly attached to the base 10, may be made rotatable thereon in order to present difierently shaped anvil surfaces to the staples. The die is normally prevented from turning on the base by means of indexing bosses 66 on the top of the base which extend into indentations in the bottom of the die. The die 13 is held down in engagement with the bosses 66 by a coil spring 67 which is compressed between the under face of the base and the head of a screw 68 which extends up through the base into the die.

Theindexing bosses 66 permit the die 13 to be turned into any one of three difi'erent angular positions. In one of the positions, the previously described clinching groove 14:

is disposed crosswise of the base. In another position, two deeper clinching grooves 69 are disposed crosswise of the base, which grooves, by reason of their increased depth, result in the production of a loose staple which is comparatively easy to remove. In the third position of the die, two other grooves 7 O and 71 are located at right angles to each other in proper position for coaction with the staple. Unlike the previously described grooves, the groove 7 0 is disposed longitudinally of the base at the location of the side of the staple, with the result that, when the staple is driven, one leg of the The arm 11, rearwardly of the head forma- .tion 15, consists of a hollow portion 72 of rectangular cross section which is rovided in its up r surface with a rearwar 1y opening slot 3 '(see Fig. 8) for the accommodation of a stud 74 on the top of the follower 18. The stud 74, which is capped by a removable nut 75, forms the connection 19 between the follower 18 and thespring 20. The portion 72 of the arm contains an inverted channel member 76 which is provided in the rear part thereof with a slot 77, also for the accommo dation of the stud 74. The channel member 76 in tum contains another considerably narrower and slightly shallower channel member 78 (see Fig. 7) which is provided along its lower edges with flange portions 79 which extend first outwardly, then upwardly, then inwardly and then downwardly in slightly spaced relation to the sides of the member, thereby producing the guideway '17 for both the staples and the follower.

The front end plates 24 and 25, between which the guideway 23 for the driving blade 22 is formed, are positioned at opposite sides of inturned flanges 80 (see Fig. 10) on the sides of the front end of the channel member 7 6 and are clamped together on the flanges by screws 81. I

.A relatively heavy plate 82 is attached at 83 to the upper surface of the front portion of the channel member 76 (see Fig. 6) in a position beneath the hammer 28 and serves as a stop for the downward movement of the latter. The plate 82 is preferably separated ends with transversely extending rubber blocks 85 which are held in place by countersunk screws 86. The blocks 85 serve to absorb in large measure any shocks or jars incident to the operation of the machine.

I claim:

1. In a stapling machine, a base which is provided at its front end with a stapleclinching die, an arm which is pivoted at its rear end to the rear end of the base and is provided at its front end with a staple-drivmg mechanism for coaction with the die, spring means for normally maintaining the front end of the arm in a raised position, an operating lever for the mechanism which is pivoted at its front end to the front end of the arm and is provided at its rear end with a handle, and spring means for normally main:

taining the'rear end of the lever in a raised position, said handle having; knob-like pormounted on the arm above the tion which is located a su antial distance in front of the pivotal connection between the arm and the base, and said first mentioned sprin means being such as to yield fully upon epression of the handle before the second mentioned spring means begins to yield, whereby to cause the staple-driv in mechanism to be moved into engagement with the die before the mechamsm commences to operate.

2; In a stapling machine, a casing, a driving hammer in the casing, a ring for advancing the hammer, means or retracting the hammer a ainst the resistance of the spring, a retainer for the spring non-rotatably mounted in the casing, and an adjusting screw for the retainer 1ournaled in the casing in threaded engagement with the retainer.

3. In a staplin machine, a casing, a driving. hammer in t e casing, a spring for advancing the hammer, means for retracting the hammer against the resistance of the spring, a retainer for the spring non-rotatably mounted in the casing, and an adjusting screw for the retainer journaled in the casing in threaded engagement with the retainer, said casing be' provided with a slot, and said retainer geing provided with a pointer which projects into the slot and indicates by its osition therein the degree of compresslon o the spring for any particular position of the retainer.

4. In a stapling machine, a spring-pressed hammer, a staple-driving blade attached to one side of the hammer 1n downwardly projecting relation to the lower end of the latter, means for retracting the hammer, means for automatically releasing the hammer as soon as the latter reaches a certain retracted position, and a compressible shock-absorbing member secured to the lower end of the hammer at one side of the blade for cushioning the action of the hammer.

5. In a stapling machine, a casing, a driving hammer in the casing, 21 in the casing above the hammer for advancing the latter, an adjustable stop for the spring, means. for retracting the hammer to compress the spring, means for automatically releasing the hammer as soon as the latter reaches a certain retracted position, and a knurled finger piece ournaled in the top of the casing in axially fixed relation thereto and coacting interiorly of thevcas' with the stop for changing the position 0 the latter and thereby varying the staple-driving force of the hammer upon rotation of the member in one direction or the other.

6. In a stapling machine, a base provided at one end with a staple-clinching die, an arm pivoted to the other end of the base, and staple-driving mechanism member for engagement with the cam-to automatically trip the hook with respect to the hammer when the latter arrives at a certain retracted position.

7. In a stapling machine, a base provided at one end with a staple-clinching die, an arm pivoted to the other end of the base, and staple-driving mechanism mounted on the arm above the die, said mechanism including a magazine for staples, means for feeding the staples one at a time from the magazine,

a blade for driving each staple against the die, a hammer connected with the blade, a spring for advancing thehammer, an operating lever, a dog carried by the lever in engagement with the hammer for retracting the hammer against the action of the spring upon depression of the lever, and means for automatlcally tripping the dog with respect to the hammer when the latter arrives at a certain retracted position, said lever being located above the arm and being provided with a knob-like handle portion between the pivotal axis of the arm and the staple-driving mechanism in substantially spaced relation to said pivotal axis.

8. In a stapling machine, a base which is provided at its front end with a staple-clinch ing die, an arm which is pivoted at its rear end to the rear end of the base and is provided at its front end with a staple-driving mechanism for coaction with the die, spring means for normally maintaining the front end of the arm in a raised position, an operating lever for the mechanism which is pivoted at its front end to the front end of the arm and is provided at its rear end with a handle, and spring means for normally maintaining the rear end ofthe lever in a raised position, said handle having a knob-like portion which is located a substantial distance in front of the pivotal connection between the arm and the base, and said first-mentioned spring means being such as to yield fully upon depression of the handle before the handle moves far-enough to operate the staple-driving mechanism, whereby to cause the mechanism to be moved into engagement with the die before the mechanism drives the staple.

EDWARD KRANTZ.

I. di sald mechanism including a magazine for 

